package com.atguigu.gulimall.cart.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.constant.CartConstant;
import com.atguigu.common.utils.R;
import com.atguigu.gulimall.cart.exception.CartExceptionHandler;
import com.atguigu.gulimall.cart.feign.ProductFeignService;
import com.atguigu.gulimall.cart.interceptor.CartInterceptor;
import com.atguigu.gulimall.cart.service.CartService;
import com.atguigu.gulimall.cart.to.UserInfoTo;
import com.atguigu.gulimall.cart.vo.CartItemVo;
import com.atguigu.gulimall.cart.vo.CartVo;
import com.atguigu.gulimall.cart.vo.SkuInfoVo;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.stream.Collectors;

/**
 * @author: kaiyi
 * @create: 2020-09-12 10:27
 */
@Slf4j
@Service
public class CartServiceImpl implements CartService {

  @Autowired
  private StringRedisTemplate redisTemplate;

  @Autowired
  private ProductFeignService productFeignService;

  @Autowired
  private ThreadPoolExecutor executor;

  @Override
  public CartItemVo addToCart(Long skuId, Integer num) throws ExecutionException, InterruptedException {

    //拿到要操作的购物车信息
    BoundHashOperations<String, Object, Object> cartOps = getCartOps();

    //判断Redis是否有该商品的信息
    String productRedisValue = (String) cartOps.get(skuId.toString());
    //如果没有就添加数据
    if (StringUtils.isEmpty(productRedisValue)) {

      //2、添加新的商品到购物车(redis)
      CartItemVo cartItemVo = new CartItemVo();
      //开启第一个异步任务
      CompletableFuture<Void> getSkuInfoFuture = CompletableFuture.runAsync(() -> {
        //1、远程查询当前要添加商品的信息
        R productSkuInfo = productFeignService.getInfo(skuId);
        SkuInfoVo skuInfo = productSkuInfo.getData("skuInfo", new TypeReference<SkuInfoVo>() {});
        //数据赋值操作
        cartItemVo.setSkuId(skuInfo.getSkuId());
        cartItemVo.setTitle(skuInfo.getSkuTitle());
        cartItemVo.setImage(skuInfo.getSkuDefaultImg());
        cartItemVo.setPrice(skuInfo.getPrice());
        cartItemVo.setCount(num);
      }, executor);

      //开启第二个异步任务
      CompletableFuture<Void> getSkuAttrValuesFuture = CompletableFuture.runAsync(() -> {
        //2、远程查询skuAttrValues组合信息
        List<String> skuSaleAttrValues = productFeignService.getSkuSaleAttrValues(skuId);
        cartItemVo.setSkuAttrValues(skuSaleAttrValues);
      }, executor);

      //等待所有的异步任务全部完成
      CompletableFuture.allOf(getSkuInfoFuture, getSkuAttrValuesFuture).get();

      String cartItemJson = JSON.toJSONString(cartItemVo);
      cartOps.put(skuId.toString(), cartItemJson);

      return cartItemVo;
    } else {
      //购物车有此商品，修改数量即可
      CartItemVo cartItemVo = JSON.parseObject(productRedisValue, CartItemVo.class);
      cartItemVo.setCount(cartItemVo.getCount() + num);
      //修改redis的数据
      String cartItemJson = JSON.toJSONString(cartItemVo);
      cartOps.put(skuId.toString(),cartItemJson);

      return cartItemVo;
    }
  }

  @Override
  public CartItemVo getCartItem(Long skuId) {
    //拿到要操作的购物车信息
    BoundHashOperations<String, Object, Object> cartOps = getCartOps();

    String redisValue = (String) cartOps.get(skuId.toString());

    CartItemVo cartItemVo = JSON.parseObject(redisValue, CartItemVo.class);

    return cartItemVo;
  }

  /**
   * 获取用户登录或者未登录购物车里所有的数据
   * @return
   * @throws ExecutionException
   * @throws InterruptedException
   */
  @Override
  public CartVo getCart() throws ExecutionException, InterruptedException {

    CartVo cartVo = new CartVo();
    UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();
    if (userInfoTo.getUserId() != null) {
      //1、登录
      String cartKey = CartConstant.CART_PREFIX + userInfoTo.getUserId();
      //临时购物车的键
      String temptCartKey = CartConstant.CART_PREFIX + userInfoTo.getUserKey();

      //2、如果临时购物车的数据还未进行合并
      List<CartItemVo> tempCartItems = getCartItems(temptCartKey);
      if (tempCartItems != null) {
        //临时购物车有数据需要进行合并操作
        for (CartItemVo item : tempCartItems) {
          addToCart(item.getSkuId(),item.getCount());
        }
        //清除临时购物车的数据
        clearCartInfo(temptCartKey);
      }

      //3、获取登录后的购物车数据【包含合并过来的临时购物车的数据和登录后购物车的数据】
      List<CartItemVo> cartItems = getCartItems(cartKey);
      cartVo.setItems(cartItems);

    } else {
      //没登录
      String cartKey = CartConstant.CART_PREFIX + userInfoTo.getUserKey();
      //获取临时购物车里面的所有购物项
      List<CartItemVo> cartItems = getCartItems(cartKey);
      cartVo.setItems(cartItems);
    }

    return cartVo;
  }

  /**
   * 获取到我们要操作的购物车
   * @return
   */
  private BoundHashOperations<String, Object, Object> getCartOps() {
    //先得到当前用户信息
    UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();

    String cartKey = "";
    if (userInfoTo.getUserId() != null) {
      //gulimall:cart:1
      cartKey = CartConstant.CART_PREFIX + userInfoTo.getUserId();
    } else {
      cartKey = CartConstant.CART_PREFIX + userInfoTo.getUserKey();
    }

    //绑定指定的key操作Redis
    BoundHashOperations<String, Object, Object> operations = redisTemplate.boundHashOps(cartKey);

    return operations;
  }


  /**
   * 获取购物车里面的数据
   * @param cartKey
   * @return
   */
  private List<CartItemVo> getCartItems(String cartKey) {
    //获取购物车里面的所有商品
    BoundHashOperations<String, Object, Object> operations = redisTemplate.boundHashOps(cartKey);
    List<Object> values = operations.values();
    if (values != null && values.size() > 0) {
      List<CartItemVo> cartItemVoStream = values.stream().map((obj) -> {
        String str = (String) obj;
        CartItemVo cartItem = JSON.parseObject(str, CartItemVo.class);
        return cartItem;
      }).collect(Collectors.toList());
      return cartItemVoStream;
    }
    return null;

  }


  @Override
  public void clearCartInfo(String cartKey) {
    redisTemplate.delete(cartKey);
  }

  @Override
  public void checkItem(Long skuId, Integer check) {

    //查询购物车里面的商品
    CartItemVo cartItem = getCartItem(skuId);
    //修改商品状态
    cartItem.setCheck(check == 1?true:false);

    //序列化存入redis中
    String redisValue = JSON.toJSONString(cartItem);

    BoundHashOperations<String, Object, Object> cartOps = getCartOps();
    cartOps.put(skuId.toString(),redisValue);

  }

  /**
   * 修改购物项数量
   * @param skuId
   * @param num
   */
  @Override
  public void changeItemCount(Long skuId, Integer num) {

    //查询购物车里面的商品
    CartItemVo cartItem = getCartItem(skuId);
    cartItem.setCount(num);

    BoundHashOperations<String, Object, Object> cartOps = getCartOps();
    //序列化存入redis中
    String redisValue = JSON.toJSONString(cartItem);
    cartOps.put(skuId.toString(),redisValue);
  }


  /**
   * 删除购物项
   * @param skuId
   */
  @Override
  public void deleteIdCartInfo(Integer skuId) {

    BoundHashOperations<String, Object, Object> cartOps = getCartOps();
    cartOps.delete(skuId.toString());
  }

  @Override
  public List<CartItemVo> getUserCartItems() {

    List<CartItemVo> cartItemVoList = new ArrayList<>();
    //获取当前用户登录的信息
    UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();
    //如果用户未登录直接返回null
    if (userInfoTo.getUserId() == null) {
      return null;
    } else {
      //获取购物车项
      String cartKey = CartConstant.CART_PREFIX + userInfoTo.getUserId();
      //获取所有的
      List<CartItemVo> cartItems = getCartItems(cartKey);
      if (cartItems == null) {
        throw new CartExceptionHandler();
      }
      //筛选出选中的
      cartItemVoList = cartItems.stream()
          .filter(items -> items.getCheck())
          .map(item -> {
            //更新为最新的价格（查询数据库）
            BigDecimal price = productFeignService.getPrice(item.getSkuId());
            item.setPrice(price);
            return item;
          })
          .collect(Collectors.toList());
    }

    return cartItemVoList;
  }

}
